Having done both Ki Aikido and Tai Chi, I came to believe that the desired results were the same- unification of the mind and body. I found the moving meditation of Tai Chi more to my liking but the principles of moving from your center, staying relaxed, dropping your breath (weight underside), and flowing (ki is extended) were the same.
I think you can also achieve this from pure yoga, pilates, chi gung, or meditation.